Language impairments in children often have devastating impacts on social, behavioral, and academic skills. Moreover, there are relatively few studies on language intervention in the literature, and those appearing are often difficult to interpret due to inherent methodological issues (e.g, very low n, differences in treatments, high subject variability, etc.) Despite this, in recent years, there have been a number of important advances in language intervention, including studies examining the importance of replicating and enhancing key behaviors found in normal parent-child interaction to effectively treat language impairments. Significant elements of this interactive model, rooted in the "transactional theory" of language development (i.e., Moerk, 1992; Yoder and Warren, 1993) and studied under the ruberic of "Milieu teaching" (Warren and Kaiser, 1986), "Conversational Recast," (Camarata, 1996; Camarata, Nelson, and Camarata, 1994; Nelson, 1989) and "naturalistic" (Camarata, 1993; Koegel, Dunlap, and Koegel, 1987) have yielded promising results, particularly when compared to treatments that do not include these elements (see the review in Camarata, 1996). Because language acquisition in children with language learning disabilities is a complex process, it is extremely important to determine which parameters should be enhanced during treatment of language impairment to achieve maximal language gain. From a broad perspective, the parameters under study include child variables, parent variables as they relate to child variables, and how these variables translate into effective interventions. This includes determining: a) which child behaviors are keystones for inducing broader levels of language advance, b) which intervention procedures will maximize acquisition of these keystone language skills, and c) whether these procedures have broad applicability to diverse populations of children with language impairments. These issues will be examined in three subprojects within an integrated program project on language intervention that includes a team of researchers specializing in language impairments in children who have extensive individual and collective expertise in treating diverse populations with language impairments.